Refractive error, or refraction error, is unpreventable but diagnosable eye problem in which the ability of eye to focus light on retina is impaired. This error produces blurry vision and visual impairment. Refractive errors can be corrected with glasses, contact lenses and refractive surgery. Most common refractive errors are • myopia i.e. nearsightedness; difficulty in seeing distant objects clearly • hyperopia i.e. farsightedness; difficulty in seeing close objects clearly • astigmatism i.e. imperfect curvature of lens and/or cornea • presbyopia i.e. age-related condition in which lens does not change its shape as rapidly as before